1. Field of the Invention
The present invention relates to a recoil starter adapted to rotate a rope reel by drawing an end of a recoil rope wound around the rope reel and drawn to the outside of a recoil rope case, transmit the rotation of the rope reel to a cam member via a damper spring, transmit the rotation of the cam member to an engine via a ratchet mechanism, and thereby start the engine.
2. Description of the Related Art
A recoil starter has already been known which is adapted to rotate a rope reel, around which a recoil rope is wound, by drawing the recoil rope, rotate a rotary member of an engine connected to a cam member, which is driven by the rope reel, via a ratchet mechanism, and thereby start the engine, wherein a damper spring wound like a return coil spring is interposed between the rope reel and cam member, the damper spring elastically connecting in the rotational direction the rope reel and cam member together via the damper spring so that the rotation made by the drawing of the recoil rope of the rope reel is transmitted to the cam member via the damper spring, a shock transmitted to the hand, which draws the recoil rope, due to the variation and the like of a load on the engine at the time of the starting thereof being thereby absorbed, the rotary member connected to the engine being rotated at a high speed by the energy accumulated in the damper spring, the starting of the engine being thereby done with ease.
In a related art recoil starter, a rope reel around which a recoil rope is wound, and a cam member connected to a rotary member fixed to an engine via a ratchet mechanism, such as a centrifugal clutch and the like are arranged in an opposed state, and an annular recess is formed in an opposed surface of each of the rope reel and cam member, a coil spring-like damper spring being housed in the annular recess, one end, which is bent in the shape of the letter “U”, of the damper spring being engaged with the rope reel with the other end, which is bent in the axial direction of the damper spring, engaged with an opening formed in the cam member, the rope reel and cam member being thereby rotatably connected together via the damper spring. When the rope reel is rotated by drawing the recoil rope wound therearound, the cam member is rotated via the damper spring, and the rotation of the cam member causes a crankshaft of an engine to be rotated via the ratchet mechanism formed between the cam member and engine, the engine being thereby started, as disclosed in JP-A-2003-336567.
According to the related techniques, the annular recess, which houses a coil spring-like damper spring therein, formed in the rope reel and cam member is provided with a boss portion extending in a projecting manner from the rope reel and cam member so that the rope reel and cam member is abutted on each other at the substantially central portion of the damper spring with respect the longitudinal direction thereof, the damper spring being arranged on the outer circumferential surfaces of the two boss portions. Therefore, when the damper spring absorbs a large load on the engine and is distorted to cause the diameter of the wound damper spring to be reduced, the damper spring is wound tightly on the outer circumferential surfaces of the boss portions of the rope reel and cam member. During this time, a part of the damper spring enters a clearance between the abutted surfaces of the two boss portions, and held therebetween. This causes the damper spring to be one-sidedly deformed, or both end portions of the damper spring are tightly wound around the boss portion of the rope reel and that of the cam member. When the rope reel and cam member in this condition are relatively rotated, only the central portion of the damper spring that is near the abutted surface of the two boss portions is greatly deformed to cause in some cases the damper spring to be broken, or the durability thereof to be spoiled.